Sandwich panel joints and methods for joining sandwich panels

ABSTRACT

Joints for joining panels together, such as for joining honeycomb sandwich panels used in aerospace applications, and methods of joining said panels are disclosed. In some examples of disclosed joints, a first panel and a second panel can be joined together to form a joint. The first panel can be a flat panel that includes a rabbet formed along a first longitudinal edge, and the second panel can be a curved panel that includes a notch formed along a second longitudinal edge. In forming the joint, a portion of the rabbet can be positioned within the notch, and the flat panel and curved panel can be oriented at a non-parallel and non-perpendicular angle to one another. Adhesive can be applied along the rabbet and/or the notch in order to secure the joint.

RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.15/301,929, entitled “SANDWICH PANEL JOINTS AND METHODS FOR JOININGSANDWICH PANELS,” filed on Oct. 4, 2016, which claims priority to PCTApplication No. PCT/US2014/039672, entitled “SANDWICH PANEL JOINTS ANDMETHODS FOR JOINING SANDWICH PANELS,” filed on May 28, 2014, and thecomplete disclosures of which are hereby incorporated by reference.

FIELD

The present disclosure relates to joints for joining panels, such as forjoining honeycomb sandwich panels used in aerospace applications, andmethods of joining said panels.

BACKGROUND

Honeycomb sandwich panels (e.g., a honeycomb core structure sandwichedbetween two layers of material, or skins) are often used in theconstruction of aircraft, because they have high strength to weightratios. Depending on the specific location and application of ahoneycomb structure in an aircraft, two or more honeycomb sections maybe required and may be joined or bonded together to define a largerhoneycomb structure. In some applications, such as joining panels inconstructing overhead storage bins for an aircraft (which can also bereferred to as a bin bucket or stow bin), a curved sandwich panel isjoined to a straight sandwich panel.

In a conventional method of joining a flat panel to a curved panel, ajoint is created by machining interlocking “fingers” in the two panelsto be joined, and adhering the panels together. A first panel 100 (FIG.1A) has a honeycomb core 104 sandwiched between a first skin layer 102and a second skin layer 103. Portions of panel 100 are machined toremove areas of skin layer 102 and some or all of core 104, therebyforming a plurality of fingers 105 and cut-outs, or recesses 106 andresulting in a staggered edge 107. In some techniques, substantially allof core 104 is removed from areas of each recess 106, such as shown inFIG. 1B. A manual scraping step is often performed to remove remnants ofcore 104 from portions 108 of each recess 106. Such scraping can resultin areas of the second skin layer 103 having no core 104 attached, butcan be difficult and time-consuming to perform.

A second panel 120 (FIG. 2) also has a honeycomb core 122 sandwichedbetween a first skin layer 124 and a second skin layer 126. Second panel120 is also machined to form a staggered edge 127 having alternatingfingers 128 and recesses 130. Each finger 128 of panel 120 is sized tocorrespond to and fit within a respective recess 106 of panel 100,resulting in a staggered joint 132 (FIG. 3). Likewise, each finger 105of panel 100 is sized to correspond to and fit within a respectiverecess 130 of panel 120. FIG. 4 shows a schematic view of joint 132.Adhesive 134 is applied along staggered edge 107 and/or staggered edge127, and the respective fingers and recesses of the two panels areinterlocked with one another to secure the joint together.

Conventional manufacturing techniques may result in inconsistentproduction results, rippling, and/or curling inwards of one or both ofthe panels. Such curling or rippling often results in buckling and/orwavy internal joints in the finished product (e.g., aircraft storagebin). Such flawed joints may be visible to airline passengers, and thusmanufacturers often must scrap or dispose of such defective parts,wasting time and money, and/or attempt to mitigate the curling, therebyincreasing production costs and time. Mitigation of the curling is oftennot entirely effective to improve the visual quality of the resultingparts and also increases production times. Thus, there remains a needfor an improved method of joining honeycomb sandwich panels.

SUMMARY

Joints for joining panels together, such as for joining honeycombsandwich panels used in aerospace applications, and methods of joiningsaid panels are disclosed. In some examples of disclosed joints, a firstpanel and a second panel can be joined together to form a joint. Thefirst panel can be a flat panel that includes a rabbet formed along afirst longitudinal edge, and the second panel can be a curved panel thatincludes a notch formed along a second longitudinal edge. In forming thejoint, a portion of the rabbet can be positioned within the notch, andthe flat panel and curved panel can be oriented at a non-parallel andnon-perpendicular angle to one another. Adhesive can be applied alongthe rabbet and/or the notch in order to secure the joint.

In some examples, a rabbet can be formed in the first panel by machiningaway a strip along the first longitudinal edge, resulting in a lip thatextends from a wall, the lip containing a small thickness of core andone layer of skin underneath. The notch can be machined into the secondlongitudinal edge of the second panel, and may be, for example, agenerally V-shaped or generally U-shaped notch. In some examples, thenotch may include three notch surfaces, or faces, where a parallel faceis parallel to one of the skins of the second panel, an angled face isarranged to form an acute angle with the other skin of the second panel,and the third notch face connects the parallel face and the angled faceto one another. The lip of the rabbet of the first panel can bepositioned on the inside of the notch such that it is adjacent (e.g., incontact with, or close to) the angled face of the notch. A top edge ofthe wall of the rabbet can intersect with the parallel face of thenotch, thereby creating a space substantially encapsulated by the rabbetand the notch. The adhesive may be substantially contained within thisspace, thereby joining the first and second panels together.

Disclosed joints and methods of forming joints can be particularlyuseful for joining a flat panel to a curved panel, such as is performedin the manufacturing of overhead storage bins for passenger aircrafts.As compared to prior art techniques, some presently disclosed methodscan reduce production time, simplify assembly and cleaning processes,improve visual appearance of the resulting parts, eliminate steps suchas scraping honeycomb core away from the panel, and/or eliminate orreduce the need to scrap parts due to defects in the joint formation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a prior art first sandwich panel havinginterlocking fingers machined along one edge.

FIG. 1B is a close-up of a portion of the prior art first sandwich panelof FIG. 1A.

FIG. 2 is a perspective view of a prior art second sandwich panel havinginterlocking fingers machined along one edge.

FIG. 3 is a perspective view of the prior art first sandwich panel ofFIG. 1A joined together with the prior art second sandwich panel of FIG.2 to form a prior art staggered joint.

FIG. 4 is a schematic view of the joint of FIG. 3.

FIG. 5 is a perspective view of an illustrative, non-exclusive exampleof an aircraft.

FIG. 6 is an exploded, schematic view of illustrative, non-exclusiveexamples of panels to be joined together according to the presentdisclosure.

FIG. 7 is a schematic view of a panel joint according to the presentdisclosure, showing the first and second panels of FIG. 6 joinedtogether.

FIG. 8 is a perspective view of a portion of a first sandwich panelaccording to the present disclosure.

FIG. 9 is a perspective view of a portion of a second sandwich panelaccording to the present disclosure.

FIG. 10 is a perspective view of the sandwich panel of FIG. 9, with anadhesive applied.

FIG. 11 is a perspective view of an overhead storage bin for an aircrafthaving a panel joint according to the present disclosure.

FIG. 12 is a schematic block diagram of illustrative, non-exclusiveexamples of methods of joining panels according to the presentdisclosure.

DESCRIPTION

In FIG. 5, an example of an aircraft 10 is generally illustrated.Aircraft 10 may take any suitable form, including commercial aircraft,military aircraft, or any other suitable aircraft. While FIG. 5illustrates an aircraft 10 in the form of a fixed wing aircraft, othertypes and configurations of aircraft are within the scope of aircraft 10according to the present disclosure, including (but not limited to)rotorcraft and helicopters.

An aircraft 10 includes one or more structures 12, which are structuresthat include one or more panels 13. Each panel 13 includes a core formedof a relatively lightweight material, such as a plurality of elongatecells, typically having hexagonal or rectangular cross-sections. Suchcores may be referred to as honeycomb cores, but other shapes andconfigurations also may be used. While other cores, such as a corrugatedstructure and/or foam materials are also possible, examples describedherein will be described with reference to honeycomb cores, andtherefore structures 12 are also referred to herein as honeycombstructures 12. Panels 13 include two skins, one skin being positioned oneach side of the honeycomb core, arranged to form a three-layer sandwichstructure, and thus are also referred to herein as honeycomb sandwichpanels 13, but panels 13 are not limited to such. The skins aretypically rigid, with the honeycomb core spanning between the skins.

Honeycomb structures 12 are used in aerospace applications because ofhigh strength to weight ratio. Honeycomb structures 12 may include oneor more honeycomb sandwich panels 13, joints formed between two or morehoneycomb sandwich panels 13, and/or three-dimensional structures formedusing one or more honeycomb sandwich panels 13. As illustrative,non-exclusive examples, honeycomb structures 12 may be utilized in suchaircraft structures as wings 14, fuselages 16, horizontal stabilizers18, overhead storage bins 20, vertical stabilizers 22, and enginehousings 24; however, other components of aircraft 10 additionally oralternatively may include honeycomb structures 12 such as honeycombsandwich panels 13 and joints formed between two or more honeycombsandwich panels 13.

FIG. 6 shows an exploded, schematic representation of illustrative,non-exclusive examples of joints 94 formed between two honeycombstructures 12 (e.g., joints 94 formed between two honeycomb sandwichpanels 13) according to the present disclosure. For example, honeycombstructures 12 may include a first panel 60 and a second panel 62. Firstpanel 60 may be composed of a first core structure 64 sandwiched betweena first skin 66 (“skin,” as used herein, also may be referred to as a“skin layer”) and a second skin 68. Likewise, second panel 62 may becomposed of a second core structure 70 sandwiched between a third skin72 and a fourth skin 74. Core structures 64, 70 may be and/or include ahoneycomb core structure and also may be referred to herein as honeycombcores 64, 70 and/or cores 64, 70. Panels 60, 62 also may be referred toherein as “sandwich panels,” and/or “honeycomb sandwich panels” and maybe examples of honeycomb sandwich panels 13. However, panels 60, 62 arenot required to be honeycomb sandwich panels 13.

In examples where first panel 60 and/or second panel 62 are examples ofhoneycomb sandwich panels 13, the honeycomb cores 64, 70 generally mayinclude a plurality of elongate cells (e.g., hexagonal cells) arrangedbetween two skins. In some examples, a honeycomb sandwich panel mayinclude a plurality of elongate hexagonal cells arranged such that thelongitudinal axis of the cells is perpendicular to the skins. Honeycombcores 64, 70 for sandwich panels 60, 62 may be constructed from anysuitable material, depending on the application therefore, including(but not limited to) aluminum, fiberglass, polypropylene, thermoplasticmaterials, metals, paper, paperboard, and fiber reinforced compositematerials, such as aramid or carbon fiber reinforced polymers. Skins 66,68, 72, 74 on either side of the cores 64, 70 may comprise, for example,fiberglass, carbon fiber, pre-impregnated fiberglass, pre-impregnatedcarbon fibers, resin, and/or any suitable coating or coatings, such aspaint or polymer film materials, such as a polyvinyl fluoride film(e.g., Tedlar®).

First panel 60 may be any suitable size and shape for a givenapplication. In some examples, first panel 60 may be a flat panel, suchthat first skin 66 is parallel to second skin 68 over the entire surfacearea of first panel 60, where each skin 66, 68 defines a flat plane. Insome examples, first panel 60 may be a curved panel, where one or bothof the first skin 66 and the second skin 68 are curved. In someexamples, first skin 66 and second skin 68 (or portions thereof) mayform concentric arcs. Similarly, second panel 62 may be a flat panel ora curved panel. In some examples, both first panel 60 and second panel62 may be flat panels. In some examples, both first panel 60 and secondpanel 62 may be curved panels. In some examples, one of first panel 60and second panel 62 may be a flat panel, while the other is a curvedpanel.

In order to form a joint between first panel 60 and second panel 62,each may have a portion of their respective cores 64, 70 removed along alongitudinal edge (e.g., first longitudinal edge 76 of first panel 60and second longitudinal edge 78 of second panel 62). Longitudinal edges76, 78 may be any edge of the respective panel 60, 62. In some examples,panels 60, 62 may be defined by four edges—two opposing edges orientedalong the length of the panels and two opposing edges oriented along thewidth of the panels. In some examples, the “length” of the panel may bethe longer of the two dimensions (e.g., the “length” or the panel may begreater than the “width” of the panel). In some examples, the “length”of the panel may be the lesser of the two dimensions, or may besubstantially equal to the width (e.g., for a square panel).Longitudinal edges 76, 78 may be an edge along the “length” or “width”of the panels, according to the present disclosure.

A portion of first skin 66 and a portion of first core 64 may be removedalong first longitudinal edge 76 to form a rabbet 80. Rabbet 80 mayextend along the entire length of first longitudinal edge 76, or rabbet80 may extend along a portion of the length of first longitudinal edge76. In some examples, rabbet 80 may extend along a majority of theentire length of first longitudinal edge 76. For example, rabbet 80 mayextend along almost the entire length of first longitudinal edge 76except for small portions at one or both ends of first longitudinal edge76.

Rabbet 80 may be defined by a wall 82 and a lip 84. In some examples, aportion of first core 64 and first skin 66 may be removed to form rabbet80 such that a surface area of first skin 66 that corresponds to thesurface area of lip 84 is removed. Further, a portion of first core 64corresponding to the same surface area may be removed, thereby exposinglip 84. Lip 84 may extend perpendicularly from wall 82, and lip 84 maybe parallel to second skin 68 and/or first skin 66. In some examples,lip 84 may extend at a non-perpendicular angle from wall 82 (e.g., at anacute or obtuse angle from wall 82) and lip 84 may not be parallel tosecond skin 68 and/or first skin 66.

First longitudinal edge 76 may be cut such that wall 82 is a verticalwall, oriented perpendicularly to first skin 66. In other examples, wall82 may be non-perpendicular with respect to first skin 66. For example,first longitudinal edge 76 may be cut such that wall 82 is angled withrespect to first skin 66. In some examples, wall 82 may form an acuteangle with first skin 66 and cut deeper into the core 64, away fromfirst longitudinal edge 76. In other examples, wall 82 may form anobtuse angle with first skin 66, terminating closer to firstlongitudinal edge 76 than where it originates at first skin 66. Wall 82may extend from first skin 66 through a portion of first core 64,towards second skin 68. In some examples, wall 82 does not extend allthe way to second skin 68, thereby leaving a portion of core 64 alonglip 84 (e.g., a thickness 85 of core 64). In some examples, wall 82 mayextend through the entire thickness of first core 64, from first skin 66to second skin 68, leaving no core 64 on some or all of the surface oflip 84, with lip 84 being defined solely by second skin 68.

As shown in FIG. 6, first core 64 may have a total thickness 65. Wall 82may have a wall thickness 83 and lip 84 may have a lip thickness 85,such that the total thickness 65 is equal to the sum of wall thickness83 and lip thickness 85. In some examples, wall thickness 83 may begreater than lip thickness 85, such that wall 82 extends through agreater portion of first core 64 than lip 84. Lip 84 thus is formed bysecond skin 68 and a portion of first core 64 corresponding to lipthickness 85. Lip 84 also may be referred to as a shelf, or flange.Rabbet 80 also may be referred to as an edge having a shelf or lipextending therefrom, a right angle groove, or as an edge with anL-shaped cross-section.

A portion of second panel 62 may be removed along second longitudinaledge 78 in order to form a notch 86. Notch 86 also may be referred to asa channel 86, a groove 86, or a recess 86. Notch 86 may extend along theentire length of second longitudinal edge 78 as shown in FIG. 6. Inother examples, notch 86 may extend along a portion of secondlongitudinal edge 78. In some examples, notch 86 may extend along amajority of the entire length of second longitudinal edge 78. Forexample, notch 86 may extend along almost the entire length of secondlongitudinal edge 78 except for small portions at one or both ends ofsecond longitudinal edge 78. To form notch 86, a portion of third skin72, fourth skin 74, and/or second core 70 may be removed from secondpanel 62 along at least a portion of second longitudinal edge 78.

Notch 86 may be formed by creating a plurality of surfaces or faceswithin the second honeycomb core 70. As used herein, the terms “surface”and “face” are not limited to smooth or flat surfaces or faces. Forexample, a surface or face can be formed by cutting into a honeycombcore (or otherwise removing a portion of a skin and underlying core), sothat the honeycomb cells within a certain area or portion of the panelhave a reduced height or thickness (the cells initially being elongatedcells having a thickness extending from one skin to the other skin ofthe panel). This can result in a surface or face defined by a pluralityof open, exposed cells (e.g., with no skin covering some of the cells),the resulting “surface” or “face” being generally defined by a planearranged at an angle to the elongated walls of the cells. In otherwords, a portion of the core of a panel can define a “surface” or a“face” via ridges of cell walls and open spaces of the cells in someexamples, rather than having a “surface” or “face” being limited toflat, or smooth surfaces or faces. In some examples, a surface or faceis generally defined by a plane oriented at a perpendicular angle to thelongitudinal axis of the cells (e.g., where a cut is made into the corethat is perpendicular to the longitudinal axis of the cells, such as inexamples with a lip that is parallel to a skin of the panel). In someexamples, a surface or face generally is defined by a plane arranged ata 180° angle (e.g., parallel to) the longitudinal axis of the cells,such as in examples with a wall that is perpendicular to a skin of thepanel). In some examples, a surface of face generally is defined by aplane arranged at a non-perpendicular and non-parallel angle to thelongitudinal axis of the cells, such as with the angled face of thenotch, or any other component of the rabbet or notch that is not formedperpendicular to or parallel to the panel skins. In any example, anon-smooth, non-uniform “surface” or “face” may be generally defined bya plurality of cut or partial cells, where the surface is formed by theridges or cell walls, in combination with the open spaces of the exposedcells.

Notch 86 can generally be described as being V-shaped, U-shaped, ortrapezoidal in some examples. Some notches 86 may include a parallelface 88, an angled face 90, and a third notch face 92 connectingparallel face 88 and angled face 90. Parallel face 88 may be parallel tofourth skin 74, and formed adjacent thereto. In some examples, parallelface 88 may be formed by a portion of fourth skin 74, such that all ofsecond core 70 is removed along parallel face 88. In some examples, asmall thickness of core 70 remains along parallel face 88 and is aparallel face thickness 89 of parallel face. Angled face 90 may beformed adjacent third skin 72, and may form a notch angle 91 with thirdskin 72. In some examples, notch angle 91 may be an acute angle. Notchangle 91

may be, for example, less than 90°, less than 60°, less than 45°, lessthan 30°, and/or less than 15°. Angled face 90 may originate at thirdskin 72 and terminate at third notch face 92. Parallel face 88 mayoriginate at fourth skin 74 and terminate at third notch face 92.

First honeycomb core 64 and second honeycomb core 70 may be removed byany suitable technique to form rabbet 80 and notch 86, respectively. Forexample, first longitudinal edge 76 and second longitudinal edge 78 maybe subject to one or more of cutting, milling, machining, grinding,laser cutting, lathing, plasma cutting, electric discharge machining,water-jet cutting, CNC machining, and/or any suitable method of removingportions of skins 66, 68, 72, 74 and/or honeycomb core layers 64, 70 toform rabbet 80 and notch 86.

An adhesive or bonding agent may be applied along at least a portion ofrabbet 80 of first panel 60 and/or along at least a portion of notch 86of second panel 62. Panels 60, 62 may then be brought together to form ajoint along longitudinal edges 76, 78, such that rabbet 80 (e.g., atleast a portion of lip 84) may be at least partially inserted into notch86. The adhesive may be substantially contained within a space formedbetween notch 86 and rabbet 80. Any suitable adhesives may be used,including epoxy adhesives (e.g., two-part epoxy adhesives), filmadhesives, foam adhesives, paste adhesives, spray adhesives,polyurethane adhesives, and/or any other bonding agent having asufficient holding strength for a particular application.

FIG. 7 shows a schematic representation of first panel 60 and secondpanel 62 joined together to form joint 94 according to the presentdisclosure. First panel 60 and second panel 62 may be joined to suchthat they are oriented at a non-parallel, non-perpendicular angle withrespect to one another. For example, first panel 60 and second panel 62may be joined to form a joint angle 95. In some examples, joint angle 95may be obtuse. For example, joint angle 95 may be greater than 90°,greater than 105°, greater than 120°, greater than 135°, greater than150°, and/or greater than 165°.

As shown in FIG. 7, at least a portion of lip 84 of rabbet 80 of firstpanel 60 may be positioned at least partially within notch 86 of secondpanel 62. For example, lip 84 of rabbet 80 of first panel 60 may bepositioned adjacent angled face 90 of notch 86. An engagement portion 98of second skin 68 along lip 84 of rabbet 80 of first panel 60 may beinserted within notch 86 such that engagement portion 98 contacts angledface 90 of notch 86 of second panel 62, as shown in FIG. 7. In someexamples, lip 84 may be inserted into notch 86 such that lip 84 contactsthird notch face 92. In other examples, lip 84 may be inserted intonotch 86 to a lesser extent, as shown in FIG. 7, such that lip 84 doesnot contact third notch face 92. In some examples, an intersection 96 ofwall 82 and first skin 66 may be positioned adjacent parallel face 88 ofnotch 86. Accordingly, in some examples, there may be little or nohoneycomb core exposed along joint 94 once first panel 60 and secondpanel 62 are brought together to form joint 94.

An adhesive 99 may be used to secure first panel 60 to second panel 62to form joint 94. For example, as shown in FIG. 7, adhesive 99 may beapplied or positioned in the space formed between rabbet 80 and notch 86(e.g., as shown in FIG. 7, the space generally defined by lip 84, wall82, parallel face 88, third notch face 92, and angled face 90). Forexample, adhesive 99 may be applied to at least a portion of rabbet 80and/or notch 86 before first panel 60 and second panel 62 are broughttogether to form joint 94. In examples where adhesive 99 is applied toor placed on rabbet 80, adhesive 99 may be applied to wall 82 and/or lip84. In examples where adhesive 99 is applied to or placed on notch 86,adhesive 99 may be applied to parallel face 88, third notch face 92,and/or angled face 90. In some examples, adhesive 99 may besubstantially contained within the space formed between rabbet 80 andnotch 86. In some examples, adhesive 99 may be present and/or applied toother areas of panels 60, 62, such as outside of the space formed byjoint 94.

Panels and joints according to the present disclosure may beincorporated into a wide variety of machines and vehicles, such as, forexample, in the manufacture of overhead storage bins for aircraft, suchas passenger airplanes. The presently disclosed joints can have generalapplicability for any manufacturing technique requiring the joining oftwo or more honeycomb sandwich panels.

Turning now to FIGS. 8-11, illustrative non-exclusive examples of panelsand joints are illustrated. Where appropriate, the reference numeralsfrom the schematic illustrations of FIGS. 6-7 are used to designatecorresponding parts of illustrated panels and joints, however, theexamples of FIGS. 8-11 are non-exclusive and do not limit the disclosedpanels and joints to the illustrated embodiments of FIGS. 8-11. That is,presently disclosed panels and joints are not limited to the specificembodiments illustrated in FIGS. 8-11, and examples disclosed herein mayincorporate any number of the various aspects, configurations,characteristics, properties, etc. of joints and panels that areillustrated in and discussed with reference to the schematicrepresentations of FIGS. 6-7 and/or the embodiments of FIGS. 1-5 and8-11, as well as variations thereof, without requiring the inclusion ofall such aspects, configurations, characteristics, properties, etc. Forthe purpose of brevity, each previously discussed component, part,portion, aspect, region, etc. or variants thereof may not be discussed,illustrated, and/or labeled again with respect to FIGS. 8-11, however,it is within the scope of the present disclosure that the previouslydiscussed features, variants, etc. may be utilized with these examples.

FIG. 8 shows an example of a first panel 60 having a rabbet 80 formedtherein, according to the present disclosure. Honeycomb core 64 may besandwiched between first skin 66 and second skin 68. Rabbet 80 may beformed along at least a portion of first longitudinal edge 76 bymachining wall 82 and lip 84 into first longitudinal edge 76, such as byremoving a portion of honeycomb core 64 and first skin 66. Wall 82 mayoriginate at first skin 66 and may extend through a portion of thethickness of core 64 towards second skin 68. A smaller portion of thecore thickness may remain on lip 84, which may extend perpendicularlyfrom wall 82. As shown in FIG. 8, first panel 60 may be a flat panel.

FIG. 9 shows an example of a second panel 62 having a notch 86 formedtherein, according to the present disclosure. Honeycomb core 70 may besandwiched between third skin 72 and fourth skin 74. Notch 86 may beformed along second longitudinal edge 78 by, for example, machiningpanel 62 along at least a portion of second longitudinal edge 78 toremove portions of second honeycomb core 70 and third skin 72. Notch 86may include parallel face 88, angled face 90, and third notch face 92.As shown in FIG. 9, second panel 62 may be a curved panel.

FIG. 10 shows a curved second panel 62 having a notch 86 formed alongsecond longitudinal edge 78, as adhesive 99 is being applied within andalong at least a portion of notch 86. FIG. 10 shows adhesive 99 in theprocess of being applied along a portion of the length of secondlongitudinal edge 78, however, adhesive 99 also may be applied along theentire length of second longitudinal edge 78. Additionally oralternatively, adhesive 99 may be applied along at least a portion ofrabbet 80 of first panel 60. In some examples, adhesive 99 may beapplied along portions of both rabbet 80 of first panel 60 and notch 86of second panel 62. In some examples, adhesive 99 may be applied alongsubstantially the entire length of rabbet 80 (e.g., along substantiallythe entire length of first longitudinal edge 76) and/or adhesive 99 maybe applied along substantially the entire length of notch 86 (e.g.,along substantially the entire length of second longitudinal edge 78).

FIG. 11 shows an overhead storage bin 1100 (also referred to as bin1100) for an aircraft, in the process of being manufactured, accordingto the present disclosure. Bin 1100 generally may include a roundedencapsulating structure 1102 that extends longitudinally to form anelongate capsule (which may be generally cylindrical in shape and/or mayhave angled or segmented walls forming the elongate capsule) that iscapped at the ends by one or more end panels 1104. As visible in FIG.11, bin 1100 may be manufactured using one or more honeycomb core panels(e.g., one or more panels 60, 62 and/or additional or alternativepanels) and joints (e.g., joints 94) between the same, according to thepresent disclosure. For example, first panel 60 (FIG. 8) and secondpanel 62 (FIGS. 9-10) may be joined to form joint 94. As seen in FIG.11, first panel 60 may be a straight, or flat panel (which can bereferred to as a batwing panel 60), and second panel 62 may be a curvedpanel (which can be referred to as a bin face panel). As seen in FIG.11, joint 94 (which is formed by joining rabbet 80 and notch 86, moreclearly visible in FIGS. 8-10) may extend along a longitudinal length1105 of bin 1100. In some examples, joint 94 (and therefore rabbet 80and notch 86) may extend along a majority of the entire length of thejoint 94 (and therefore along a majority of the entire length of thelongitudinal edge of panel 60 forming the rabbet and a majority of theentire length of the longitudinal edge of panel 62 forming the notch).In the example shown in FIG. 11, joint 94 may extend along the entirelongitudinal length 1105 of bin 1100 except for one or more tabs 1106positioned adjacent the end panels 1104. For example, one tab 1106 maybe positioned at each end of bin 1100, adjacent each end panel 1104.

FIG. 12 illustrates a block diagram of illustrative, non-exclusiveexamples of methods of making joints according to the presentdisclosure. For example, methods 1200 of forming a joint between a firstpanel and a second panel are described. The first panel may have a firsthoneycomb core having a first thickness, the first honeycomb core beingsandwiched between a first skin and a second skin. The second panel mayhave a second honeycomb core having a second thickness, the secondhoneycomb core being sandwiched between a third skin and a fourth skin.According to disclosed methods, a rabbet can be created along at least aportion of a first longitudinal edge of the first panel at 1202 byremoving a first portion of the first honeycomb core and the first skinalong the first longitudinal edge of the first panel. Creating therabbet at 1202 may include one or more of cutting, milling, machining,and scraping the first honeycomb core and the first skin. In someexamples, presently disclosed methods may eliminate the need to scrapecore from the second skin. For example, some methods of creating arabbet can result in a portion (e.g., a small thickness) of coreremaining on the second skin to form a lip portion of the rabbet. Thelip may extend from a wall (e.g., a vertical wall) formed by the firsthoneycomb core, the wall being perpendicular to the first skin andsecond skin. The lip may extend perpendicular from the wall, or mayextend at some other angle from the wall. The lip may be formed fromportions of the second skin and the first honeycomb core. Advantageouslymachining the rabbet along a straight line according to the presentdisclosure advantageously may be faster than machining a staggeredarrangement of a plurality of fingers and recesses.

Further, a notch can be created at 1204 along at least a portion of asecond longitudinal edge of the second panel by removing a portion ofthe second honeycomb core and the third skin along the secondlongitudinal edge of the second panel. The notch may include a parallelface that is parallel to the third skin and fourth skin and an angledface. The notch also may include a third notch face disposed between theangled face and the parallel face, connecting the two, to form a notchthat can be described as generally V-shaped or U-shaped. The angled facemay form an acute angle with the third skin. Creating the notch at 1204may include one or more of cutting, milling, machining, and scraping thesecond honeycomb core and the third skin. Advantageously machining thenotch along a straight line according to the present disclosureadvantageously may be faster than machining a staggered arrangement of aplurality of fingers and recesses.

Methods also may include inserting at least a portion of the rabbet intothe notch at 1210 to form the joint between the first panel and thesecond panel. In some methods, inserting at least a portion of therabbet into the notch at 1210 may include inserting at least a portionof the lip into the notch. For example, a portion of the second skin maybe in contact with the angled face of the notch once the two panels arejoined together. In some examples, the rabbet may be inserted all theway into the notch until the lip contacts the notch and is preventedfrom being further inserted into the notch (e.g., by bringing the lipinto contact with the third notch face). In some examples, the rabbetmay be inserted partially into the notch such that the lip does notcontact the third notch face. In some methods, an intersection of thevertical wall and first skin contacts the parallel face of the notch.This arrangement can essentially form an enclosed space between therabbet and the notch, wherein an adhesive can be substantiallycontained.

Prior to or concurrent with inserting the rabbet into the notch at 1210,an adhesive may be applied along at least a portion of the firstlongitudinal edge at 1206 and/or an adhesive may be applied along atleast a portion of the second longitudinal edge at 1208. Advantageously,presently disclosed methods may allow for application of adhesive alonga straight line (e.g., along the rabbet and/or along the notch). Suchapplication of adhesive can be more efficient and less time-consumingthan methods that require application of adhesive along a non-straight(e.g., staggered) path.

In some methods, the rabbet of the first panel may be pressed into thenotch of the second panel at 1212. The third skin of the second panelmay be pressed against the lip of the first panel in order to form atight seal at the joint between the two panels. This interface (e.g.,the interior of the joint; the mating of the second skin and third skin)may form part of an interior surface of a storage bin (also referred toas a bin bucket) for an aircraft. This is a highly visible area on manypassenger airplanes, and is subject to buckling and rippling when panelsare joined using prior art techniques. The presently disclosed methodsof joining two or more honeycomb panels together can avoid or reducethis buckling in some examples, which in turn may reduce having todispose of defective and/or unsightly parts. Some methods can providefor a clean, straight joint appearance on the interior of a storage bin.For example, the notch of the second panel can be machined andconfigured to receive the lip of the rabbet on the first panel so thatbuckling of the second skin of the first panel does not occur.

After the first panel and second panel have been assembled together toform a joint, any excess adhesive optionally may be removed or cleanedfrom the joint at 1214. The joint then may be clamped or otherwisesecured to hold the panels in position while the adhesive dries and/orcures.

FIG. 12 schematically provides a flowchart that represents illustrative,non-exclusive examples of methods according to the present disclosure.In FIG. 12, some steps are illustrated in dashed boxes indicating thatsuch steps may be optional or may correspond to an optional version of amethod according to the present disclosure. That said, not all methodsaccording to the present disclosure are required to include the stepsillustrated in solid boxes. The methods and steps illustrated in FIG. 12are not limiting and other methods and steps are within the scope of thepresent disclosure, including methods having greater than or fewer thanthe number of steps illustrated, as understood from the discussionsherein.

Illustrative, non-exclusive examples of inventive subject matteraccording to the present disclosure are described in the followingenumerated paragraphs:

A1. A joint, comprising:

a first panel having a first honeycomb core having a first thickness,the first honeycomb core being sandwiched between a first skin and asecond skin, wherein a first longitudinal edge of the first panel has arabbet formed along a majority of an entire length of the firstlongitudinal edge;

a second panel having a second honeycomb core having a second thickness,the second honeycomb core being sandwiched between a third skin and afourth skin, wherein a second longitudinal edge of the second panel hasa notch formed along a majority of an entire length of the secondlongitudinal edge, wherein at least a portion of the rabbet ispositioned within the notch such that the first longitudinal edge andthe second longitudinal edge are aligned to form the joint; and anadhesive applied to at least one of the first longitudinal edge and thesecond longitudinal edge.

A2. The joint of paragraph A1, wherein at least one of the first paneland the second panel is a flat panel.

A3. The joint of paragraphs A1 or A2, wherein at least one of the firstpanel and the second panel is a curved panel.

A4. The joint of any of paragraphs A1-A3, wherein the second skin of thefirst panel and the third skin of the second panel are oriented at ajoint angle with respect to one another, the joint angle beingnon-parallel and non-perpendicular.

A5. The joint of paragraph A4, wherein the joint angle is obtuse.

A6. The joint of any of paragraphs A1-A5, wherein the adhesive issubstantially contained within a space formed between the notch and therabbet.

A7. The joint of any of paragraphs A1-A6, wherein the rabbet is definedby a vertical wall cut into the first honeycomb core, the vertical walloriginating at the first skin, wherein the vertical wall isperpendicular to the first skin, and wherein the vertical wall extendsfrom the first skin through a first portion of the first thickness ofthe first honeycomb core.

A8. The joint of paragraph A7, wherein the rabbet includes a lip thatextends perpendicularly from the vertical wall, the lip being formed bythe second skin and a second portion of the first thickness of the firsthoneycomb core, the second portion being less than the first portion.

A9. The joint of any of paragraphs A1-A8, wherein the notch is at leastone of V-shaped, U-shaped, and trapezoidal.

A10. The joint of any of paragraphs A1-A9, wherein the notch comprises aparallel face that is parallel to the fourth skin and an angled facethat is arranged at a notch face angle to the third skin.

A11. The joint of paragraph A10, wherein the notch face angle is acute.

A12. The joint of any of paragraphs A8-A11, wherein the lip of therabbet of the first panel is positioned within the notch.

A13. The joint of any of paragraphs A10-A12, wherein the lip of therabbet of the first panel is adjacent the angled face of the notch ofthe second panel.

A14. The joint of any of paragraphs A10-A13, wherein an intersection ofthe vertical wall and the first skin is adjacent the parallel face ofthe notch of the second panel.

A15. The joint of any of paragraphs A10-A14, wherein an engagementportion of the second skin along the lip of the rabbet of the firstpanel is inserted within the notch of the second panel such that theengagement portion contacts the angled face of the notch of the secondpanel.

A16. The joint of any of paragraphs A10-A15, wherein the notch furthercomprises a third notch face that connects the parallel face to theangled face, wherein the angled face originates at the third skin, andthe parallel face originates at the fourth skin.

A17. The joint of paragraph A16, wherein the angled face, the parallelface, and the third notch face together form a generally V-shaped notch.

A18. The joint of paragraph A16, wherein the angled face, the parallelface, and the third notch face together form a trapezoidal notch.

A19. The joint of paragraph A16, wherein the angled face, the parallelface, and the third notch face together form a generally U-shaped notch.

B1. An overhead storage bin for an aircraft, the overhead storage bincomprising the joint of any of paragraphs A1-A19.

C1. An aircraft comprising the overhead storage bin of paragraph B1.

D1. A method of forming a joint between a first panel and a secondpanel, the first panel having a first honeycomb core having a firstthickness, the first honeycomb core being sandwiched between a firstskin and a second skin, and the second panel having a second honeycombcore having a second thickness, the second honeycomb core beingsandwiched between a third skin and a fourth skin, the methodcomprising:

creating a rabbet along a first longitudinal edge of the first panel byremoving a first portion of the first honeycomb core and the first skinalong the first longitudinal edge of the first panel;

creating a notch along a second longitudinal edge of the second panel byremoving a second portion of the second honeycomb core and the thirdskin along the second longitudinal edge of the second panel, wherein thenotch includes a parallel face that is parallel to the third skin andfourth skin and an angled face, the angled face forming an acute anglewith the third skin; and

inserting at least a portion of the rabbet into the notch to form thejoint between the first panel and the second panel.

D2. The method of paragraph D1, wherein the creating the rabbetcomprises one or more of cutting, milling, machining, and scraping thefirst honeycomb core and the first skin.

D3. The method of any of paragraphs D1-D2, wherein the creating thenotch comprises one or more of cutting, milling, machining, and scrapingthe second honeycomb core and the third skin.

D4. The method of any of paragraphs D1-D3, further comprising applyingan adhesive along the first longitudinal edge.

D5. The method of any of paragraphs D1-D4, further comprising applyingan adhesive along the second longitudinal edge.

D6. The method of any of paragraphs D1-D5, wherein the creating therabbet comprises creating a rabbet having a lip extending from avertical wall formed by the first honeycomb core, the vertical wallbeing perpendicular to the first skin and second skin, wherein the lipis formed from portions of the second skin and the first honeycomb core.

D7. The method of paragraph D6, wherein the inserting at least a portionof the rabbet into the notch comprises inserting at least a portion ofthe lip into the notch.

D8. The method of any of paragraphs D6-D7, wherein the inserting atleast a portion of the rabbet into the notch comprises inserting the lipinto the notch such that a portion of the second skin contacts theangled face of the notch.

D9. The method of any of paragraphs D6-D8, wherein the inserting atleast a portion of the rabbet into the notch comprises inserting therabbet such that an intersection of the vertical wall and first skincontacts the parallel face of the notch.

D10. The method of any of paragraphs D1-D9, further comprising:

applying an adhesive along at least one of the first longitudinal edgeand the second longitudinal edge;

pressing the rabbet of the first panel into the notch of the secondpanel; and

removing excess adhesive from the joint.

As used herein, the terms “selective” and “selectively,” when modifyingan action, movement, configuration, or other activity of one or morecomponents or characteristics of an apparatus, mean that the specificaction, movement, configuration, or other activity is a direct orindirect result of user manipulation of an aspect of, or one or morecomponents of, the apparatus.

As used herein, the terms “adapted” and “configured” mean that theelement, component, or other subject matter is designed and/or intendedto perform a given function. Thus, the use of the terms “adapted” and“configured” should not be construed to mean that a given element,component, or other subject matter is simply “capable of” performing agiven function but that the element, component, and/or other subjectmatter is specifically selected, created, implemented, utilized,programmed, and/or designed for the purpose of performing the function.It is also within the scope of the present disclosure that elements,components, and/or other recited subject matter that is recited as beingadapted to perform a particular function may additionally oralternatively be described as being configured to perform that function,and vice versa. Similarly, subject matter that is recited as beingconfigured to perform a particular function may additionally oralternatively be described as being operative to perform that function.

The various disclosed elements of apparatuses and steps of methodsdisclosed herein are not required to all apparatuses and methodsaccording to the present disclosure, and the present disclosure includesall novel and non-obvious combinations and subcombinations of thevarious elements and steps disclosed herein. Moreover, one or more ofthe various elements and steps disclosed herein may define independentinventive subject matter that is separate and apart from the whole of adisclosed apparatus or method. Accordingly, such inventive subjectmatter is not required to be associated with the specific apparatusesand methods that are expressly disclosed herein, and such inventivesubject matter may find utility in apparatuses and/or methods that arenot expressly disclosed herein.

The invention claimed is:
 1. A joint, comprising: a first panel having afirst honeycomb core having a first thickness, the first honeycomb corebeing sandwiched between a first skin and a second skin, wherein a firstlongitudinal edge of the first panel has a rabbet formed along amajority of an entire length of the first longitudinal edge; a secondpanel having a second honeycomb core having a second thickness, thesecond honeycomb core being sandwiched between a third skin and a fourthskin, wherein a second longitudinal edge of the second panel has a notchformed along a majority of an entire length of the second longitudinaledge, wherein the notch is formed in the second honeycomb core, betweenthe third skin and the fourth skin, and wherein at least a portion ofthe rabbet is positioned within the notch such that the firstlongitudinal edge and the second longitudinal edge are aligned to formthe joint; and an adhesive applied to at least one of the firstlongitudinal edge and the second longitudinal edge.
 2. The jointaccording to claim 1, wherein the second skin of the first panel and thethird skin of the second panel are oriented at a joint angle withrespect to one another, the joint angle being non-parallel andnon-perpendicular.
 3. The joint according to claim 2, wherein the jointangle is obtuse.
 4. The joint according to claim 1, wherein the adhesiveis substantially contained within a space formed between the notch andthe rabbet.
 5. The joint according to claim 1, wherein the rabbet isdefined by a wall cut into the first honeycomb core, the walloriginating at the first skin, wherein the wall is perpendicular to thefirst skin, and wherein the wall extends from the first skin through afirst portion of the first thickness of the first honeycomb core.
 6. Thejoint according to claim 5, wherein the rabbet includes a lip thatextends perpendicularly from the wall, the lip being formed by thesecond skin and a second portion of the first thickness of the firsthoneycomb core, the second portion being less than the first portion. 7.The joint according to claim 6, wherein the notch is V-shaped.
 8. Thejoint according to claim 6, wherein the notch comprises a parallel facethat is parallel to the fourth skin and an angled face that is arrangedat a notch face angle to the third skin, wherein the notch face angle isacute.
 9. The joint according to claim 8, wherein the lip of the rabbetof the first panel is positioned within the notch of the second panel.10. The joint according to claim 9, wherein the lip of the rabbet of thefirst panel is adjacent the angled face of the notch of the secondpanel.
 11. The joint according to claim 10, wherein an intersection ofthe wall and the first skin is adjacent the parallel face of the notch.12. The joint according to claim 11, wherein an engagement portion ofthe second skin along the lip of the rabbet of the first panel isinserted within the notch of the second panel such that the engagementportion contacts the angled face of the notch of the second panel. 13.The joint according to claim 12, wherein the notch further comprises athird notch face that connects the parallel face to the angled face,wherein the angled face originates at the third skin, and the parallelface originates at the fourth skin.
 14. The joint according to claim 13,wherein the first panel is a flat panel and the second panel is a curvedpanel.
 15. A method of forming a joint between a first panel and asecond panel, the first panel having a first honeycomb core having afirst thickness, the first honeycomb core being sandwiched between afirst skin and a second skin, and the second panel having a secondhoneycomb core having a second thickness, the second honeycomb corebeing sandwiched between a third skin and a fourth skin, the methodcomprising: creating a rabbet along a first longitudinal edge of thefirst panel by removing a first portion of the first honeycomb core andthe first skin along the first longitudinal edge of the first panel;creating a notch along a second longitudinal edge of the second panel byremoving a second portion of the second honeycomb core and the thirdskin along the second longitudinal edge of the second panel, wherein thenotch includes a parallel face that is parallel to the third skin andthe fourth skin and an angled face, the angled face forming an acuteangle with the third skin; and inserting at least a portion of therabbet into the notch to form the joint between the first panel and thesecond panel.
 16. The method according to claim 15, wherein the creatingthe rabbet comprises one or more of cutting, milling, machining, andscraping the first honeycomb core and the first skin, and wherein thecreating the notch comprises one or more of cutting, milling, machining,and scraping the second honeycomb core and the third skin.
 17. Themethod according to claim 15, further comprising applying an adhesivealong one or more of the first longitudinal edge and the secondlongitudinal edge.
 18. The method according to claim 15, wherein thecreating the rabbet comprises creating a rabbet having a lip extendingfrom a wall formed by the first honeycomb core, the wall beingperpendicular to the first skin and second skin, wherein the lip isformed from portions of the second skin and the first honeycomb core,and wherein the inserting at least a portion of the rabbet into thenotch comprises inserting the lip into the notch such that a portion ofthe second skin contacts the angled face of the notch.
 19. The methodaccording to claim 18, further comprising: applying an adhesive along atleast one of the first longitudinal edge and the second longitudinaledge; pressing the rabbet of the first panel into the notch of thesecond panel; and removing excess adhesive from the joint.
 20. Themethod according to claim 19, wherein the first panel is a flat paneland the second panel is a curved panel.